Process for the preparation of siloxane copolymers and resin compositions containing the siloxane copolymers prepared by the process

ABSTRACT

This invention relates to a process of producing a siloxane copolymer comprising the step of reacting at least one diol, at least one dicarbonate and at least one silicon compound as copolymerization components in the presence of an esterification or transesterification catalyst, wherein the silicon compound is represented by the general formulas (I) and (II):                    
     wherein R 1 , R 2 , R 3  and R 4  are each independently a hydrogen atom or a substituted or non-substituted organic group; X and Y are each independently a hydrogen atom or a substituted or non-substituted organic group; a represents an integer of 0 to 5,000; and b represents an integer of 3 to 20.

TECHNICAL FIELD

This invention relates to a new process for the preparation of siloxanecopolymers and resin compositions containing the siloxane copolymersprepared by the process.

BACKGROUND ART

Thermoplastic resins are industrially useful molding materials forplastic containers, film, fiber, adhesives, extruded sheets and thelike. Such thermoplastic resins (for example, polycarbonate resin whosemain unit is 2,2-bis(4-hydroxyphenyl)propane (bisphenol A)) hasexcellent mechanical and electric properties, heat resistance,dimensional stability, transparency and moldability. However, suchthermoplastic resin has disadvantages in flammability, production of atoxic gas upon burning or the like.

Since thermoplastic resins usually have high flammability, thethermoplastic resin is generally made fire-retardant by adding afire-retardant, typically a halogen or a phosphorous compound, in theapplication where fire-retardance is required. However, these fireretardants are not preferred from the environmental viewpoint becausethey produce a more toxic gas upon burning than the thermoplastic resinitself. Moreover, there are problems in a fire retardant such as thatthe properties of a thermoplastic resin such as mechanical and electricproperties, heat resistance, weatherability or the like may decreasedependent on the amount of it added.

As a means to improve fire retardance and moldability of thermoplasticresins, a method in which a siloxane compound is added to thermoplasticresins has been proposed. However, this method has a problem that fireretardance and moldability may not be sufficient, or the siloxanecompound may bleed on the surface of a molded article of a thermoplasticresin when the compatibility of a siloxane compound with a thermoplasticresin is low.

As a means to solve the above-mentioned problems, a technique concerningto a method for producing a siloxane copolymer has been proposed. Forexample, in Japanese Laid-Open Publication No. 2-196823, JapaneseLaid-Open Publication No. 3-106937 and Japanese Laid-Open PublicationNo. 7-2999, a method for producing a polyestercarbonate-siloxanecopolymer by an interfacial polycondensation method using bisphenolderivatives, dicarboxylic acid dichloride, phosgene and phenolterminated dimethylpolysiloxane has been proposed. Moreover, in JapaneseLaid-Open Publication No. 5-222173, a method for producing apolyestercarbonate-siloxane copolymer by an interfacial polycondensationmethod using phenol terminated dimethylpolysiloxane has been proposed.However, in interfacial such polycondensation methods, there areproblems that phosgene and acid chloride, which are raw materials, arenot easily available, and using a halogen compound such as methylenechloride is not preferred from the environmental viewpoint.

As a means to solve problems in the interfacial polycondensation method,in Japanese Laid-Open Publication No. 4-91125, a method for producing apolyester-siloxane block copolymer by a molten condensationpolymerization method using dicarboxylic acid diester, diol and phenolterminated dimethylpolysiloxane has been proposed. However, in thismethod, because of using an expensive and special silicon compound,there are problems that the production cost is high and when the amountof siloxane unit introduced into the block copolymer increases, thephysical properties (for example, mechanical strength) decrease due to aphase separation.

On the other hand, Curry et al have proposed a method for producing asiloxane copolymer to be obtained from a diol andbis(anilino)diphenylsilane (J. Appl. Polym. Sci., vol.9, pp. 295(1965)). In this method, since the polymer produced becomes analternating copolymer, it becomes possible to increase the introducedamount of siloxane. However, in this method, because of using anexpensive and special silicon compound, the production cost becomes highand further there is a problem that it takes a long time period for thereaction. Also, there is a problem that heat-resistance of the obtainedsiloxane copolymer is inferior.

The purpose of this invention is to provide a method to overcome theabove-mentioned problems existing in the above-mentioned conventionalmethod for producing a siloxane copolymer and to produce a siloxanecopolymer having excellent mechanical properties (for example, strength,breaking elongation and impact resistance), heat-resistance,fire-retardance, moldability (for example, mold releasing property,surface lubricating property) and transparency in more easily and moreinexpensive (that is industrially and commercially advantageous).Moreover, another purpose of this invention is to provide a resincomposition containing siloxane copolymer obtained by the method.

DISCLOSURE OF THE INVENTION

This invention is a process of producing a siloxane copolymer comprisingthe step of reacting at least one diol, at least one dicarbonate and asilicon compound in the presence of an esterification ortransesterification catalyst, wherein said silicon compound is at leastone compound selected from the group consisting of compounds representedby the general formulas (I) and (II):

wherein R¹, R², R³, R⁴, X and Y are each independently a hydrogen atom,a halogen atom, a hydroxide group, an amino group or a substituted ornon-substituted organic group; a represents an integer from 0 to 5000and b represents an integer from 3 to 20.

In a preferred embodiment, the above-mentioned diol is represented bythe following general formula (III):

HO—R⁵—OH   (III)

wherein R⁵ is a bivalent hydrocarbon group having 1 to 20 carbon atomswherein at least some of the hydrogen atoms in the hydrocarbon group maybe substituted with at least one group selected from a halogen atom, ahydrocarbon group, an alkoxy group and a phenoxy group; or —R⁶—A—R⁷—,wherein R⁶ and R⁷ are each independently a bivalent aromatic hydrocarbongroup having 6 to 20 carbon atoms; and A is selected from the groupconsisting of a single bond, —O—, —S—, —SO—, —SO₂—, —CO— and a bivalenthydrocarbon group containing 1 to 20 carbon atoms.

In a preferred embodiment, the process further comprises the step ofreacting at least one diester of a dicarboxylic acid. The diester of adicarboxylic acid is represented by the following general formula (IV):

wherein R⁸ is a bivalent hydrocarbon group having 1 to 20 carbon atomswherein at least some of the hydrogen atoms in the hydrocarbon group maybe substituted with at least one group selected from a halogen atom, ahydrocarbon group, an alkoxy group and a phenoxy group; or —R¹⁰—D—R¹¹—,and R⁹ is a hydrocarbon group having 1 to 20 carbon atoms, wherein R¹⁰and R¹¹ are each independently a bivalent aromatic hydrocarbon grouphaving 6 to 20 carbon atoms; and D is selected from the group consistingof a single bond, —O—, —S—, —SO—, —SO₂—, —CO— and a bivalent hydrocarbongroup having 1 to 20 carbon atoms.

In a preferred embodiment, the above-mentioned dicarbonate isrepresented by the following general formula (V):

wherein R¹² represents a hydrocarbon group having 1 to 20 carbon atoms.

In a preferred embodiment, the above-mentioned silicon compound is atleast one selected from the group consisting of polydimethylsiloxane,polymethylphenylsiloxane, dimethoxydimethylsilane,dimethoxydiphenylsilane, octamethylcyclotetrasiloxane andoctaphenylcyclotetrasiloxane.

In a preferred embodiment, the above-mentioned diol is at least oneselected from the group consisting of 2,2-bis(4-hydroxyphenyl)propane,1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,bis(4-hydroxyphenyl)sulfone, 9,9-bis(4-hydroxyphenyl)fluorene.

In a preferred embodiment, the above-mentioned diester of dicarboxylicacid is at least one selected from the group consisting ofdiphenylterephthalate, diphenylisophthalate, dimethylterephthalate anddimethylisophthalate.

In a preferred embodiment, the above-mentioned dicarbonate isdiphenylcarbonate.

In a preferred embodiment, the above-mentioned esterification ortransesterification catalyst is tin compound.

In a preferred embodiment, the above-mentioned esterification ortransesterification catalyst is at least one selected from the groupconsisting of an acetate, a carbonate, a borate, an oxide, a hydroxide,a hydride, an alcholate and a phenolate of a metal selected from thegroup consisting of lithium, sodium, potassium, magnesium, calcium,barium, strontium zinc, cadmium, titanium, zirconium, antimony, lead,manganese or cobalt.

In a preferred embodiment, the above-mentioned esterification ortransesterification catalyst is used in the range of 0.0001 to 1.0 partsby weight based on 100 parts by weight of the siloxane copolymerobtained.

Moreover, this invention relates to a fire retardant resin compositioncontaining the siloxane copolymer obtained by the above-mentionedprocess.

Moreover, this invention relates to a resin composition for moldingcontaining the siloxane copolymer obtained by the above-mentionedprocess.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is IR spectrum of the polyester-siloxane copolymer obtained byExample 1.

FIG. 2 is IR spectrum of the polyestercarbonate-siloxane copolymerobtained by Example 5.

FIG. 3 is IR spectrum of the polycarbonate-siloxane copolymer obtainedby Example 7.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter this invention is described in detail.

A process of producing a siloxane copolymer of this invention, comprisesthe step of reacting at least one diol, at least one dicarbonate and atleast one specific silicon compound in the presence of an esterificationor transesterification catalyst.

A silicon compound used in this invention is at least one selected fromthe compounds represented by the above-mentioned general formulas (I)and (II). In the general formulas (I) and (II), R¹, R², R³, R⁴, X and Yare each independently a hydrogen atom, a halogen atom, a hydroxidegroup, an amino group or a substituted or non-substituted organic group,a is an integer of 0 to 5000, preferably an integer of 0 to 100, morepreferably of 0 to 50; b is an integer of 3 to 20, preferably 3 to 10,more preferably from 3 to 4. Examples of the substituted ornon-substituted organic group include a hydrocarbon group, an alkoxygroup, a phenoxy group, an ammonium salt-containing group, an alkylaminogroup, a carboxyl group, an ester group, a polyether group, an epoxygroup, a vinylether group, a vinylester group, an acryl group, amethacryl group, a mercapto group and an isocyanate group. Examples ofthe hydrocarbon group include a linear or branched alkyl group having 1to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1to 6 carbon atoms, and a linear or branched alkenyl group, an alkylarylgroup having 6 to 20 carbon atoms, preferably 6 to 14 carbon atoms, morepreferably 6 to 10 carbon atoms and cycloalkyl group. As long as notdetracting from the advantage of this invention, at least some of thehydrogen atoms of the hydrocarbon group can be substituted with anarbitrary substituent. Examples of the substituent include a hydroxylgroup, a halogen atom, an alkoxy group, a phenoxy group, an amino group,an ammonium salt-containing group, an alkylamino group, a carboxylgroup, an ester group, a polyether group, an epoxy group, a vinyl group,a vinylether group, a vinylester group, an allyl group, an acryl group,a methacryl group, a mercapto group and an isocyanate group.Hereinafter, unless otherwise clearly indicated, the term “hydrocarbongroup” includes the above-mentioned substituted or non-substitutedhydrocarbon groups.

The substituted or non-substituted organic group is preferably ahydrocarbon group, an alkoxy group or a phenoxy group, more preferably amethyl group, a phenyl group, a methoxy group, an ethoxy group or aphenoxy group, most preferably a methyl group and a methoxy group. Sincea silicon compound having these substituents is easily available, asimple process of producing a siloxane copolymer can be achieved.

Examples of the above-mentioned silicon compound include: alkoxysilanessuch as dimethoxydimethylsilane, diethoxydimethylsilane,octadecyltrimethoxysilane, octadecyltriethoxysilane,octadecylmethyldimethoxysilane, vinylmethyldiethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane, 5-hexenyltrimethoxysilane,methylphenyldimethoxysilane, methylphenyldiethoxysilane,diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltrimethoxysilane,phenyltriethoxysilane, cyclohexylmethyldimethoxysilane,N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane,3-aminopropyltriethoxysilane, 3-chloropropylmethyldimethoxysilane,(3-glycydoxypropyl)methyldiethoxysilane, and3-methacryloxypropylmethyldimethoxysilane, phenylsilanes such asdiphenylsilane, diphenylsilanediol, cyclic siloxanes such ashexamethylcyclotrisiloxane, hexaphenylcyclotrisiloxane,octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane,1,3,5,7-tetramethylcyclotetrasiloxane,1,3,5,7-tetravinyltetramethylcyclotetrasiloxane,decamethylcyclopentasiloxane, hexamethyldisiloxane,octamethyltrisiloxane, decamethyltetrasiloxane,dodecamethylpentasiloxane, tetradecamethylhexasiloxane,hexadecamethylheptasiloxane, octadecamethyloctasiloxane,eicosamethylnonasiloxane, docosamethyldecasiloxane,3,3-diphenylhexamethyltrisiloxane, siloxane oligomers, polysiloxanessuch as polydimethylsiloxane, polymethylphenylsiloxane,polydiphenylsiloxane, alkyl-modified polysiloxane, methacryl-modifiedpolysiloxane, chloroalkyl-modified polysiloxane, fluoro-modifiedpolysiloxane, polyether-modified polysiloxane, alchol-modifiedpolysiloxane, amino-modified polysiloxane, epoxy-modified polysiloxane,phenol-modified polysiloxane, carboxy-modified polysiloxane andmercapto-modified polysiloxane. These silicon compounds can be usedalone or in combination thereof.

Among these silicon compounds, polydimethylsiloxane,polymethylphenylsiloxane, dimethoxydimethylsilane,dimethyoxydiphenylsilane, octamethylcyclotetrasiloxane andoctaphenylcyclotetrasiloxane is preferred because the raw materialsthereof are easily available. Polydimethylsiloxane,dimethoxydimethylsilane and octamethylcyclotetrasiloxane is especiallypreferred.

The diol used for the process of this invention is preferablyrepresented by the above-mentioned general formula (III).

In the general formula (III), R⁵ is a bivalent hydrocarbon group having1 to 20 carbon atoms wherein at least some of the hydrogen atoms in thehydrocarbon group may be substituted with at least one substituentselected from the group consisting of a halogen atom, a hydrocarbongroup, an alkoxy group and a phenoxy group; or —R⁶—A—R⁷—, R⁶ and R⁷ areeach independently a bivalent aromatic hydrocarbon group having 6 to 20carbon atoms, more preferably 6 to 14 carbon atoms, most preferably 6 to10 carbon atoms; and A is selected from the group consisting of a singlebond, —O—, —S—, —SO—, —SO₂—, —CO—, and a bivalent hydrocarbon grouphaving 1 to 20 carbon atoms. Preferably A is a single bond, —O—, —SO₂—or a bivalent hydrocarbon group having 1 to 20 carbon atoms, morepreferably —SO₂— or a bivalent hydrocarbon group having 1 to 14 carbonatoms.

Examples of the above-mentioned diol include: aromatic diols such as2,2-bis(4-hydroxyphenyl)propane (bisphenol A),bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3,5-dimethylphenyl)methane,bis(4-hydroxy-3,5-dichlorophenyl)methane,1,1-bis(4-hydroxyphenyl)cyclohexylmethane,1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane,1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC),4,4′-dihydroxydiphenylether, bis(4-hydroxy-3,5-dimethylphenyl)ether,bis(4-hydroxyphenyl)sulfone, bis(4-hydroxy-3,5-dimethylphenyl)sulfone,4,4′-dihydroxybenzophenone,2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, tetrabromobisphenol A,tetrachlorobisphenol A, dihydroxydiphenyl, hydroquinone, resorcinol,dihydroxynaphthalene, dihydroxyanthracene, phenolphthalein, fluorescein,2,2′-dihydroxy-1,1-dinaphthylmethane, 4,4′-dihydroxydinaphthyl,9,9-bis(4-hydroxyphenyl)fluorene and aliphatic diols such as ethyleneglycol, propylene glycol, tetramethylene glycol, diethylene glycol,triethylene glycol, polyethylene glycol, 1,3-propanediol,1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol,1,6-hexanediol and 1,10-decanediol. These diols can be used alone or incombinations thereof.

Among these diol, bisphenol A, bisphenol TMC,bis(4-hydroxyphenyl)sulfone and 9,9-bis(4-hydroxyphenyl)fluorene arepreferred, because the copolymer obtained has excellent properties (forexample, heat-resistance, mechanical property, fire retardance) and rawmaterials thereof are easily available. Bisphenol A is especiallypreferred. When using bis(4-hydroxyphenyl)sulfone or9,9-bis(4-hydroxyphenyl)fluorene, a copolymer having excellent fireretardance can be obtained.

The process of this invention further comprises the step of reacting atleast one diester of a dicarboxylic acid as a copolymerizationcomponent. This diester of a dicarboxylic acid is preferably representedby the above-mentioned general formula (IV). In the general formula(IV), R⁸ is a bivalent hydrocarbon group having 1 to 20 carbon atomswherein at least some of the hydrogen atoms in the hydrocarbon group maybe substituted with at least one substituent group selected from thegroup consisting of a halogen atom, a hydrocarbon group, an alkoxy groupand a phenoxy group or —R¹⁰—D—R¹¹—; and R⁹ is a hydrocarbon group having1 to 20 carbon atoms, preferably 1 to 10, more preferably 1 to 6. R¹⁰and R¹¹ are independently a bivalent aromatic hydrocarbon group having 6to 20, preferably 6 to 14, more preferably 6 to 10 carbon atoms; and Dis selected from the group consisting of a single bond, —O—, —S—, —SO—,—SO₂—, —CO— and a bivalent hydrocarbon group having 1 to 20 carbonatoms. Preferably, D is a single bond, —O—, —SO₂— or a bivalenthydrocarbon group having 1 to 20 carbon atoms, more preferably —SO₂— ora bivalent hydrocarbon group having 1 to 14 carbon atoms.

Examples of the above-mentioned diester of a dicarboxylic acid include:dimethyl, diethyl, dipropyl, dibutyl, dicyclohexyl and diphenylesters ofan aromatic dicarboxylic acid such as terephthalic acid,methoxyterephthalic acid, ethoxyterephthalic acid, fluoroterephthalicacid, chloroterephthalic acid, methylterephthalic acid, isophthalicacid, phthalic acid, methoxyisophthalic acid, methylisophthalic acid,diphenylmethane-4,4′-dicarboxylic acid,diphenylmethane-3,3′-dicarboxylic acid, diphenylether-4,4′-dicarboxylicacid, diphenyl-4,4′-dicarboxylic acid, naphthalene-1,4-dicarboxylicacid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylicacid and the like, an aliphatic dicarboxylic acid such as oxalic acid,malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid,azelaic acid, sebacic acid, dodecanedicarboxylic acid, 3-methylazelaicacid and the like, an alicyclic dicarboxylic acid such as1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid,1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid,1,5-decahydronaphthalenedicarboxylic acid,2,6-decahydronaphthalenedicarboxylic acid,2,7-decahydronaphthalenedicarboxylic acid and the like. These diester ofdicarboxylic acid can be used alone or in combination thereof.

Among these diesters of dicarboxylic acid, diphenylterephthalate,diphenylisophthalate, dimethylterephthalte and dimethylisophthalate arepreferred and, diphenylterephthalate and diphenylisophthalate areespecially preferred because reactivity thereof is high and rawmaterials thereof are easily available and the copolymer obtainedexhibits excellent properties (for example, heat-resistance, mechanicalproperty or fire retardance).

The dicarbonate used in the process of this invention is preferablyrepresented by the above-mentioned general formula (V). In the generalformula (V), R¹² is a hydrocarbon group having 1 to 20 carbon atoms,preferably 1 to 10, more preferably 1 to 6.

Examples of the dicarbonate include dimethylcarbonate, diethylcarbonate,dipropylcarbonate and diphenylcarbonate. Among the above-mentioneddicarbonates, dipheylcarbonate is especially preferred because of itshigh reactivity and availability.

Examples of the combination of above-mentioned starting materials usedin the process of this invention include a combination of diol/siliconcompound/dicarbonate. The range of molar ratio of the combination ispreferably 1/0.4˜2/0.4˜2, more preferably 1/0.5˜1/0.5˜1. Especiallypreferred combinations include 1/0.5/1 and 1/0.5/0.5. In the case ofsuch combination, a polycarbonate-siloxane copolymer is produced.

Particular examples of the combination include:

Bisphenol A and dimethoxymethylsilane and diphenylcarbonate (molarratio: 1/0.5/1 or 1/0.5/0.5);

Bisphenol A and polydimethylsiloxane and diphenylcarbonate (molar ratio:1/0.5/1 or 1/0.5/0.5);

Bisphenol A and octamethylcyclotetrasiloxane and diphenylcarbonate(molar ratio: 1/0.5/1 or 1/0.5/0.5);

Bisphenol TMC and dimethoxymethylsilane and diphenylcarbonate (molarratio: 1/0.5/1 or 1/0.5/0.5);

Bisphenol TMC and polydimethylsiloxane and diphenylcarbonate (molarratio: 1/0.5/1 or 1/0.5/0.5); and

Bisphenol TMC and octamethylcyclotetrasiloxane and diphenylcarbonate(molar ratio: 1/0.5/1 or 1/0.5/0.5).

Particularly, a combination of bisphenol A and dimethoxymethylsilane anddiphenylcarbonate (molar ratio: 1/0.5/1 or 1/0.5/0.5), and a combinationof bisphenol A and polydimethylsiloxane and diphenylcarbonate (molarratio: 1/0.5/1 or 1/0.5/0.5) is preferred, and the combination ofbisphenol A and dimethoxymethylsilane and diphenylcarbonate (molarratio: 1/0.5/1 or 1/0.5/0.5) is especially preferred because thesecompounds are readily available and reactivity thereof is high and thecopolymer obtained exhibits especially excellent properties (forexample, heat-resistance, mechanical property and fire retardance).

Moreover, in the process of this invention, when optionally using adiester of dicarboxylic acid as a starting material, examples ofcombinations of starting materials are as follows:

Diol/dicarboxylic acid diester/silicon compound/dicarbonate. The rangeof molar ratio of such combination is preferably 1/0.5˜2/0.5˜2/0.1˜2,more preferably 1/0.5˜1/0.5˜1/0.5˜1. Particularly preferred combinationsinclude 1/1/1/1 and 1/0.5/0.5/0.5. In the case of such combinations, apolyester-siloxane copolymer is produced.

Also preferred range of molar ratio of the combinations ofdiol/dicarboxylic acid diester/silicon compound/dicarbonate is1/0.1˜0.45/0.1˜0.45/1, more preferably 1/0.2˜0.45/0.2˜0.45/0.5˜1.Particularly preferred combinations include 1/0.4/0.4/1 and1/0.4/0.4/0.5. In the case of such combinations, apolyestercarbonate-siloxane copolymer is produced.

Specific examples of the combination include:

Bisphenol A, diphenylterephthalate, diphenylisophthalate,dimethoxydimethylsilane and diphenylcarbonate (molar ratio:1/0.5/0.5/1/1, 1/0.25/0.25/0.5/0.5, 1/0.2/0.2/0.4/1 or1/0.2/0.2/0.4/0.5);

Bisphenol A, diphenylisophthalate, dimethoxydimethylsilane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5);

Bisphenol A, diphenylterephthalate, dimethoxydimethylsilane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5);

Bisphenol A, diphenylterephthalate, diphenylisophthalate,polydimethylsiloxane and diphenylcarbonate (molar ratio: 1/0.5/0.5/1/1,1/0.25/0.25/0.5/0.5, 1/0.2/0.2/0.4/1 or 1/0.2/0.2/0.4/0.5);

Bisphenol A, diphenylisophthalate, polydimethylsiloxane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5);

Bisphenol A, diphenylterephthalate, polydimethylsiloxane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5);

Bisphenol A, diphenylterephthalate, diphenylisophthalate,octamethylcyclotetrasiloxane and diphenylcarbonate (molar ratio:1/0.5/0.5/1/1, 1/0.25/0.25/0.5/0.5, 1/0.2/0.2/0.4/1 or1/0.2/0.2/0.4/0.5);

Bisphenol A, diphenylisophthalate, octamethylcyclotetrasiloxane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5);

Bisphenol A, diphenylterephthalate, octamethylcyclotetrasiloxane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5);

Bisphenol TMC, diphenylterephthalate, diphenylisophthalate,dimethoxydimethylsilane and diphenylcarbonate (molar ratio:1/0.5/0.5/1/1, 1/0.25/0.25/0.5/0.5, 1/0.2/0.2/0.4/1 or1/0.2/0.2/0.4/0.5);

Bisphenol TMC, diphenylisophthalate, dimethoxydimethylsilane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5);

Bisphenol TMC, diphenylterephthalate, dimethoxydimethylsilane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5);

Bisphenol TMC, diphenylterephthalate, diphenylisophthalate,polydimethylsiloxane and diphenylcarbonate (molar ratio: 1/0.5/0.5/1/1,1/0.25/0.25/0.5/0.5, 1/0.2/0.2/0.4/1 or 1/0.2/0.2/0.4/0.5);

Bisphenol TMC, diphenylisophthalate, polydimethylsiloxane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5);

Bisphenol TMC, diphenylterephthalate, polydimethylsiloxane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5);

Bisphenol TMC, diphenylterephthalate, diphenylisophthalate,octamethylcyclotetrasiloxane and diphenylcarbonate (molar ratio:1/0.5/0.5/1/1, 1/0.25/0.25/0.5/0.5, 1/0.2/0.2/0.4/1 or1/0.2/0.2/0.4/0.5);

Bisphenol TMC, diphenylisophthalate, octamethylcyclotetrasiloxane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5); and

Bisphenol TMC, diphenylterephthalate, octamethylcyclotetrasiloxane anddiphenylcarbonate (molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or1/0.4/0.4/0.5).

The above-mentioned combinations are particularly preferred due to theready availability and high reactivity of each starting material andproperties of the copolymer obtained (for example, heat-resistance,mechanical property and fire retardance). Particularly the combinationsof bisphenol A, diphenylterephthalate, diphenylisophthalate,dimethoxydimethylsilane and diphenylcarbonate (molar ratio:1/0.5/0.5/1/1, 1/0.25/0.25/0.5/0.5, 1/0.2/0.2/0.4/1 or1/0.2/0.2/0.4/0.5); bisphenol A, diphenylisophthalate,dimethoxydimethylsilane and diphenylcarbonate (molar ratio: 1/1/1/1,1/0.5/0.5/0.5, 1/0.4/0.4/1 or 1/0.4/0.4/0.5); bisphenol A,diphenylterephthalate, dimethoxydimethylsilane and diphenylcarbonate(molar ratio: 1/1/1/1, 1/0.5/0.5/0.5, 1/0.4/0.4/1 or 1/0.4/0.4/0.5) arepreferred. The combinations of Bisphenol A, diphenylterephthalate,dimethoxydimethylsilane and diphenylcarbonate (molar ratio: 1/1/1/1,1/0.5/0.5/0.5, 1/0.4/0.4/1 or 1/0.4/0.4/0.5), and bisphenol A,diphenylterephthalate, diphenylisophthalate, dimethoxydimethylsilane anddiphenylcarbonate (molar ratio: 1/0.5/0.5/1/1, 1/0.2/0.2/0.4/1,1/0.25/0.25/0.5/0.5 or 1/0.2/0.2/0.4/0.5) are especially preferred.

As a catalyst for the process of this invention, the knownesterification or transesterification catalysts can be used. Examples ofthese catalysts include an acetate, a carbonate, a borate, an oxide, ahydroxide, a hydride, an alcholate and a phenolate of an alkali metalsuch as lithium, sodium, potassium, an alkali-earth metal such asmagnesium, calcium, barium, strontium, transition metal such as zinc,cadmium, titanium, zirconium, tin, antimony, lead, manganese, cobalt.These esterification or transesterification catalysts can be used aloneor in combination thereof.

Among these catalysts, in view of the balance between the reactivity ofthe above-mentioned esterification or transesterification catalyst andthe properties of the copolymer obtained (for example, heat-resistance,mechanical property, hue), tin compounds are especially preferred.Examples of the tin compounds include acyltin, tetraacyl stannate,dibutyltin oxide, dibutyltin diacetate, dibutyltin laurate, dimethyltinmaleate, tin dioctanoate, tin tetraacetate, stannous chloride, stannicchloride, stannous acetate, trichlorobutyltin, dichlorodibutyltin,stannous oxide and stannic oxide.

The amount of these catalysts is not particularly limited, but ispreferably in the range of 0.0001 parts by weight to 1.0 parts byweight, more preferably in the range of 0.0005 parts by weight to 0.1parts by weight based on 100 parts by weight of the siloxane copolymerobtained. When the amount of the catalyst is less than 0.0001 parts byweight, the reaction is not completed, while when it is more than 1.0parts by weight, coloration of the polymer produced becomes intense andproperties such as hydrolysis-resistance become inadequate.

In the process of this invention, use of a two step reaction atdifferent temperatures is preferred. The first reaction step may becarried out under atmospheric pressure at preferably 80° C. to 250° C.,more preferably 120° C. to 230° C. The following second reaction stepmay be carried out under reduced pressure (preferably from 6 Pa to 133Pa, more preferably 6 Pa to 66 Pa) at preferably 200° C. to 400° C.,more preferably 230° C. to 320° C. By use of such two step reactions atdifferent temperatures, the siloxane copolymer of desired molecularweight can be obtained at a high yield. This is because the removal ofthe unreacted monomers may be obtained by performing the first stepreaction under atmospheric pressure. However, this invention is notlimited to the above-mentioned two step reaction, the invention may becarried out at multi-step including various temperatures and pressuresor at the same temperature and pressure.

When the two step reaction is included in the process of this invention,a transesterification reaction of diol, dicarbonate and silicon compound(or silicon compound and diester of dicarboxylic acid) occurs to form asiloxane oligomer in the first step. Next, in the second step, byplacing the reaction system under reduced pressure, thetransesterification reaction proceeds further to form a siloxanecopolymer with high molecular weight.

In the process of this invention, by adjusting the reaction conditionsand the amounts of each reaction component appropriately, a variety ofsiloxane copolymers can be produced. In the process of this invention,when a diester of dicarboxylic acid is used as an additional startingmaterial and a ratio of more than 1 mol of the sum of the diester ofdicarboxylic acid and the silicon compound to 1 mol of diol is used, thecarbonate moiety which appears to be produced by a reaction of diol withdicarbonate may be reacted completely and disappears during thepolymerization, thereby forming a polyester-siloxane copolymer. Incontrast, when a ratio of less than 1 mol of the sum of the diester ofdicarboxylic acid and the silicon compound to 1 mol of diol is used, thecarbonate moiety may not be completely reacted during the polymerizationand remains, thereby forming a polyestercarbonate-siloxane copolymer.Also, when not using the diester of dicarboxylic acid, apolycarbonate-siloxane copolymer can be obtained.

In this invention, an appropriate auxiliary solvent such asdiphenylether, biphenyl, substituted cyclohexane, decahydronaphthalene,1,2,4,5-tetramethylbenzene, or a material with which the polymerproduced is incompatible (for example, poly(fluorinated alkyleneoxide))can be used. In the process of this invention, a random copolymer can beobtained.

The siloxane copolymer obtained by the process of this invention can bemolded after being pelletized (or being chipped) or directly molded in adesired shape using an extruder.

The siloxane copolymer obtained by the process of this invention can beblended with the known other resins, or additives can be added to thecopolymer if necessary.

Examples of the above-mentioned other known resins include athermoplastic resin such as polyethylene, polypropylene, polystyrene,polymethylmethacrylate, polyamide, polycarbonate, polyester,polyphenyleneoxide, polysulfone, a thermosetting resin such as phenolresin, epoxy resin, an elastomer such as isoprene rubber, butadienerubber, acryl rubber. Examples of the above-mentioned additives includestabilizer, pigment, dye, fluorescent brightening agent, nucleous agent,polymerization accelerator, filler and reinforcing material (forexample, glass fiber, carbon fiber). By using the present siloxanecopolymer in combination with other resins and/or additives, a resincomposition which can provide an article having desired properties (forexample, transparency, mechanical and electrical properties,heat-resistance, weatherability) depending on the purpose can beobtained.

The siloxane copolymer obtained by the process of this invention can beused as a main component of fire retardant resin composition or as afire retardant to improve fire retardance of known other resins (forexample, a fire retardant of a resin composition for molding). The term“main component” as used in this specification means major containedcomponent in the composition.

When the siloxane copolymer obtained by the process of this invention isused as the main component of fire retardant resin composition (when atleast 30% by weight, preferably at least 50% by weight of the siloxanecopolymer of this invention is contained in the composition), the weightaverage molecular weight is preferably 10,000 to 300,000, morepreferably 20,000 to 100,000, most preferably 40,000 to 80,000. When theweight average molecular weight is less than 10,000, the mechanicalproperties of the article obtained are often inadequate. When it exceeds300,000, the moldability of the resin composition is often inadequate.On the other hand, when the siloxane copolymer obtained by the processof this invention is used as a fire retardant for a resin composition(when the siloxane copolymer of this invention is contained in thecomposition in the range of 1.0% by weight to 30% by weight, morepreferably 10% by weight to 20% by weight), its weight average molecularweight is preferably from 2,000 to 100,000, more preferably from 2,000to 60,000, most preferably 5,000 to 40,000. When the weight averagemolecular weight is less than 2,000, the mechanical properties of thearticle obtained are often inadequate. When it exceeds 100,000, themoldability of the composition is often inadequate.

Molecular weight of the siloxane copolymer obtained by the process ofthis invention can be adjusted by a method which is known to theordinary skilled person, such as by adjusting the amounts of a catalystto be added.

The siloxane copolymer obtained by the process of this invention hasexcellent fire retardance, transparency and moldability (for example,mold releasing property and surface lubricating property). Thus, thesiloxane copolymer obtained by the process of this invention retains theadvantages of the conventional siloxane copolymer and has better fireretardance than that of the conventional siloxane copolymer.

The siloxane copolymer obtained by the process of this invention can bewidely used to produce molded articles, fiber, filament, film and thelike. Moreover, since the siloxane copolymer obtained by the process ofthis invention has excellent fire retardance, transparency andmoldability (for example, mold releasing property and surfacelubricating property), a resin composition for molding having excellentfire retardance, transparency, and moldability (for example, moldreleasing property and surface lubricating property) as well as requiredproperties depending on the purpose can be obtained by blending thiscopolymer with other arbitrary resins having required properties. Suchresin composition for molding can be especially suitably used forarticles to be required high heat-resistance, stiffness, hydrolysisresistance, creep resistance and the like (for example, in the field ofelectricity, illumination and automobiles).

Hereinafter, the effects of the invention are described.

The process of producing a siloxane copolymer of this inventioncomprises the step of reacting at least one diol, a diester ofdicarboxylic acid if necessary, at least one dicarbonate and a specificsilicon compound in the presence of an esterification ortransesterification catalyst. By combining these specific startingmaterials, a siloxane copolymer having excellent fire retardance,transparency and moldability (for example, mold releasing property andsurface lubricating property) can be obtained. Moreover, these startingmaterials are readily available and highly reactive. Accordingly, bycombining these specific starting materials, a siloxane copolymer havingthe above-mentioned excellent properties can be produced easily andinexpensively. As mentioned above, the process of this invention hasextremely excellent advantages industrially and commercially.

EXAMPLES

The present invention will be described below by way of illustrativeexamples, however, this invention is not limited to the followingexamples. Various other modifications can be made without departing fromthe scope and spirit of this invention.

The characteristics of the polymer were measured according to thefollowing method.

(1) weight average molecular weight (Mw) of the polymer

Mw was measured by a gel-permeation chromatography (GPC) method using a510 type GPC system (Waters Co.) with chloroform as a moving phase at apolymer concentration of 2 mg/ml and a column temperature of 35° C. Mwwas calculated using polystyrene as a standard sample.

(2) glass transition temperature (Tg/° C.) of the polymer

Tg was measured by a differential scanning thermal analysis with DSC-7(Perkin-Elmer Co.) under nitrogen atmosphere at a rate of temperatureincrease of 20° C./min.

(3) silicon atom content (Si/% by weight) in the polymer

After a heat treatment of the polymer with sulfuric acid, sodiumcarbonate and calcium carbonate were added. Then the polymer was heattreated in an electric furnace, silicon atom content in the polymer wasmeasured by ICP (Inductively Coupled Plasma) emission spectrometeranalysis.

(4) melt viscosity (Mv/poise) of the polymer

Measurement was carried out by using capilograph PD-C (TOYO SEIKISEISAKUSYO Co. Ltd.) at 300° C. and shear rate of 1216 sec⁻¹.

(5) fire retardance of the polymer

After drying the pelletized polymer under a reduced pressure for 15hours at 120° C., a sample of ⅛ inch thickness was prepared by injectionmolding and evaluated according to UL-94V standard.

(6) transparency (T/%) of the polymer

By using NDH-Σ 80 (NIHON DENSYOKU KOGYO), all ray permeability of asample of ⅛ inch thickness made by injection molding was measured.

Example 1

1140 g (5.0 mol) of bisphenol A (Shinnittetsu Chemistry Co. Ltd.), 1590g (5.0 mol) of diphenylterephthalate, 1070 g (5.0 mol) ofdiphenylcarbonate (TOKYO KASEI CHEMICAL INDUSTRY Co. Ltd.), 600 g (5.0mol) of dimethoxydimethylsilane (TOKYO KASEI CHEMICAL INDUSTRY Co.Ltd.), 585 mg (1.7 mmol) of dibutyltin diacetate were charged into a 14L reaction vessel equipped with a stirrer, an inlet for introducingnitrogen, a condenser and a distillation outlet. Degassing (60 Pa) andnitrogen purges with an ultra high purity nitrogen was repeated threetimes then, under an ultra high purity nitrogen atmosphere, heating wasstarted. After stirring for 30 minutes at an inner temperature of 180°C. under an atmospheric pressure, the inner temperature was raised to210° C. and stirred for 30 minutes. Next, the inner temperature wasraised to 270° C. over 60 minutes during which time by-products weredistilled off from the distillation outlet of the reaction vessel. Thepressure of the reaction system was reduced to 133 Pa over 30 minutes,and then, held for 2 hours. After stopping stirring, the pressure of thereaction system was raised to atmospheric pressure by introducingnitrogen, and the polymer obtained was taken out of the reaction vessel.Next, this polymer was dissolved in methylene chloride and purified byre-precipitating the polymer by means of pouring the solution into amass volume of hexane.

IR spectrum of the polymer obtained is shown in FIG. 1. As shown in FIG.1, an absorption at 1740 cm⁻¹ attributable to a carbonyl (C═O)stretching vibration originated from the ester bond was confirmed in thepolymer obtained. Moreover, in the polymer obtained, an absorption atthe range of 910 cm⁻¹ to 940 cm⁻¹ attributable to an Si—O stretchingvibration originated from the O—Si—R (aromatic) bond was confirmed. Thesilicon atom content was measured to be 4.0% by weight using ICPemission spectrometer analysis method after alkali fusion of thepolymer. From the above-mentioned result, the polymer obtained wasconfirmed to be a polyester-siloxane copolymer.

The copolymer obtained was evaluated according to the above-mentionedmethods (1)˜(6). The evaluation results are shown in Table 1.

Example 2

The polymer was obtained according to Example 1 except for using 370 g(repeating unit 5.0 mol) of polydimethylsiloxane (silicone oil KF968(Shin-etsu Chemical Industry Co. Ltd.)) instead ofdimethoxydimethylsilane.

By the same analysis as Example 1, the polymer obtained was confirmed tobe a polyester-siloxane copolymer.

The copolymer obtained was evaluated according to the above-mentionedmethods (1)˜(6). The evaluation results are shown in Table 1.

Example 3

The polymer was obtained according to Example 1 except for using 109 g(repeating unit 5.0 mol) of polymethylphenylsiloxane (silicone oil KF54(Shin-etsu Chemical Industry Co. Ltd.)) instead ofdimethoxydimethylsilane.

By the same analysis as Example 1, the polymer obtained was confirmed tobe a polyester-siloxane copolymer.

The copolymer obtained was evaluated according to the above-mentionedmethods (1)˜(6). The evaluation results are shown in Table 1.

Example 4

The polymer was obtained according to Example 1 except for using 795 g(2.5 mol) of diphenylisophthalate and 795 g (2.5 mol) ofdiphenylterephthalate instead of diphenylterephthalate.

By the same analysis as Example 1, the polymer obtained was confirmed tobe a polyester-siloxane copolymer.

The copolymer obtained was evaluated according to the above-mentionedmethods (1)˜(6). The evaluation results are shown in Table 1.

Example 5

The polymer was obtained according to Example 1 except for using 636 g(2.0 mol) of diphenylterephthalate and 240 g (2.0 mol) ofdimethoxydimethylsilane.

The IR spectrum of the polymer obtained is shown in FIG. 2. As shown inFIG. 2, in the polymer obtained, absorptions at 1740 cm⁻¹ attributableto a carbonyl (C═O) stretching vibration originated from the ester bondand at 1775 cm⁻¹ attributable to a carbonyl (C═O) stretching vibrationoriginated from the carbonate bond were confirmed. Moreover, in thepolymer obtained, an absorption at the range of 910 cm⁻¹ to 940 cm⁻¹attributable to an Si—O stretching vibration originated from the O—Si—R(aromatic) bond was confirmed. The silicon atom content was measured tobe 2.2% by weight using ICP emission spectrometer analysis method afteralkali fusion of the polymer. From the above-mentioned result, thepolymer obtained was confirmed to be a polyestercarbonate-siloxanecopolymer.

The copolymer obtained was evaluated according to the above-mentionedmethods (1)˜(6). The evaluation results are shown in Table.1.

Example 6

The polymer was obtained according to Example 1 except for using 1750 g(5.0 mol) of 9,9-bis(4-hydroxyphenyl)fluorene (Shinnittetsu Chemical Co.Ltd.,) instead of bisphenol A.

By the same analysis as Example 1, the polymer obtained was confirmed tobe a polyester-siloxane copolymer.

The copolymer obtained was evaluated according to the above-mentionedmethods (1), (3), (5) and (6). The evaluation results are shown in Table1.

Example 7

The polymer was obtained according to Example 1 except for using 120 g(1.0 mol) of dimethoxydimethylsilane without usingdiphenylterephthalate.

IR spectrum of the polymer obtained is shown in FIG. 3. As shown in FIG.3, in the polymer obtained, an absorption at the 1775 cm⁻¹ carbonyl(C═O) stretching vibration originated from the carbonate bond wasconfirmed. Moreover, in the polymer obtained, an absorption at the rangeof 910 cm⁻¹ to 940 cm⁻¹ attributable to an Si—O stretching vibrationoriginated from the O—Si—R (aromatic) bond was confirmed. The siliconatom content was measured to be 2.0% by weight using ICP emissionspectrometer analysis after alkali fusion of the polymer. From theabove-mentioned results, the polymer obtained was confirmed to be apolycarbonate-siloxane copolymer.

The copolymer obtained was evaluated according to the above-mentionedmethods (1)˜(6). The evaluation results are shown in Table 1.

Example 8

The polymer was obtained according to Example 7 except for using 74 g(repeating unit 1.0 mol) of polydimethylsiloxane (Shin-etsu ChemicalIndustry Co. Ltd., silicone oil KF968) instead ofdimethoxydimethylsilane.

By the same analysis as Example 1, the polymer obtained was confirmed tobe a polycarbonate-siloxane copolymer.

The copolymer obtained was evaluated according to the above-mentionedmethods (1)˜(6). The evaluation results are shown in Table 1.

Example 9

The polymer was obtained according to Example 7 except for using 109 g(repeating unit 1.0 mol) of polymethylphenylsiloxane (Shin-etsu ChemicalIndustry Co. Ltd., silicone oil KF54) instead ofdimethoxydimethylsilane.

By the same analysis as Example 1, the polymer obtained was confirmed tobe a polycarbonate-siloxane copolymer.

The copolymer obtained was evaluated according to the above-mentionedmethods (1)˜(6). The evaluation results are shown in Table 1.

Comparative Example 1

Commercially available polycarbonate resin (TEIJIN KASEI Co., Ltd.,Panlight L-1250) was evaluated according to the above-mentioned methods(1), (2) and (4)˜(6). The evaluation results are shown in Table 1.

TABLE 1 Si content (% by Tg Mv Fire T Mw weight) (° C.) (poise)retardance (%) Example 1 56,000 4.0 131 4,500 V-0 89 Example 2 48,0003.3 138 6,000 V-0 88 Example 3 53,000 3.6 132 5,000 V-0 90 Example 445,000 3.9 129 3,500 V-0 88 Example 5 56,000 2.2 130 4,000 V-0 89Example 6 40,000 3.0 — — V-0 87 Example 7 58,000 2.0 125 3,000 V-0 88Example 8 63,000 1.9 128 4,000 V-0 87 Example 9 59,000 2.0 124 3,000 V-090 Comparative 62,000 — 147 8,000 V-2 90 Example 1

As shown in Table 1, the siloxane copolymer obtained by the process ofthis invention has the same or better transparency and moldability (forexample, mold releasing property and surface lubricating property) thanthe polycarbonate resin. Also, it can be seen that the siloxanecopolymer obtained by the process of this invention has been remarkablyimproved in fire retardance compared with the polycarbonate resin.

Example 10

30 parts by weight of the each polymer obtained from Examples 1 and 7was added to 100 parts by weight of commercially available polycarbonateresin (Panlight L-1250 (TEIJIN KASEI Co. Ltd.)), and melted and kneadedby using a double screw extruder (LABOTEX (NIHON SEIKOUJYO Co. Ltd.)) toobtain pellet-like resin compositions, respectively. By injectionmolding of these resin compositions, ⅛ inch thick samples were prepared,and fire retardance was evaluated respectively. In the case of usingpolycarbonate resin only (the above-mentioned Comparative Example 1),the evaluation of fire retardance according to UL-94V standard was V-2.In contrast, the evaluation of fire retardance of the resin compositionshaving the siloxane copolymer obtained by Examples 1 and 7 were bothV-0. The siloxane copolymer obtained by the process of this inventionwas also confirmed to have an excellent function as a fire retardantwhich gives fire retardance to known thermoplastic resins.

This invention involves a process of producing a siloxane copolymerhaving better fire retardance, transparency and moldability (forexample, mold releasing property and surface lubricating property) thana siloxane copolymer obtained by the conventional method, and whichprocess can be practiced more simply and less expensively. In addition,this invention also involves a resin composition containing a siloxanecopolymer obtained by the process of the present invention, therebyexhibiting good fire retardance and moldability.

POSSIBLE INDUSTRIAL APPLICAPABILITY

The siloxane copolymer obtained by the process of this invention hasexcellent fire retardance, transparency and moldability (for example,mold releasing property and surface lubricating property). And it isespecially superior in fire retardance without sacrificing the otheradvantageous properties. Accordingly, the siloxane copolymer obtained bythe process of this invention is especially useful for articles in whichhigh heat-resistance is required. The siloxane copolymer obtained by theprocess of this invention is useful as a main component of a fireretardant resin composition or a molding resin composition, and alsouseful as a fire retardant to improve fire retardance of other resins.

Accordingly, the siloxane copolymer obtained by the process of thisinvention, and the fire retardant resin composition containing saidcopolymer, and the molding resin composition are especially suitable forarticles in the field of electricity, illumination and automobiles.

What is claimed is:
 1. A process of producing a random siloxanecopolymer comprising the step of reacting at least one diol, at leastone dicarbonate and a silicon compound as copolymerization components inthe presence of an esterification or transesterification catalyst,wherein said silicon compound is at least one selected from the groupconsisting of compounds represented by the general formulas (I) and(II):

wherein R¹, R², R³, R⁴, X and Y are each independently a hydrogen atom,a halogen atom, a hydroxyl group, an amino group, or a substituted ornon-substituted organic group; a represents an integer of 0 to 5,000;and b represents an integer of 3 to 20; further comprising the step ofreacting at least one diester of a dicarboxylic acid as an additionalcopolymerization component, wherein said diester of a dicarboxylic acidis represented by the general formula (IV):

wherein R⁸ is a bivalent hydrocarbon group having 1 to 20 carbon atomswherein at least some of the hydrogen atoms in the hydrocarbon group maybe substituted with at least one group selected from a halogen atom, ahydrocarbon group, an alkoxy group and a phenoxy group; or —R¹⁰—D—R¹¹—,and R⁹ is a hydrocarbon group having 1 to 20 carbon atoms, wherein R¹⁰and R¹¹ are each independently a bivalent aromatic hydrocarbon grouphaving 6 to 20 carbon atoms; and D is selected from the group consistingof a single bond, —O—, —S—, —SO—, —SO₂—, —CO— and a bivalent hydrocarbongroup having 1 to 20 carbon atoms.
 2. A process of producing a randomsiloxane group comprising the step of reacting at least one diol, atleast one dicarbonate and a silicon compound as copolymerizationcomponents in the presence of an esterification or transesterificationcatalyst, wherein said silicon compound is at least one selected fromthe group consisting of compounds represented by the general formulas(I) and (II):

wherein R¹, R², R³, R⁴, X and Y are each independently a hydrogen atom,a halogen atom, a hydroxyl group, an amino group, or a substituted ornon-substituted organic group; a represents an integer of 0 to 5,000;and b represents an integer of 3 to 20; and wherein said step furthercomprises reacting a diester of dicarboxylic acid is at least oneselected from the group consisting of diphenylterephthalate,diphenylisophthalate, dimethylterephthalate and dimethylisophthalate asa copolymerization component.
 3. A process of producing a randomsiloxane copolymer comprising the step of reacting at least one diol, atleast one dicarbonate and a silicon compound as copolymerizationcomponents in the presence of an esterification and transesterificationcatalyst, wherein said silicon compound is at least one selected fromthe group consisting of compounds represented by the general formulas(I) and (II):

wherein R¹, R², R³, R⁴, X and Y are each independently a hydrogen atom,a halogen atom, a hydroxyl group, an amino group, or a substituted ornon-substituted organic group; a represents an integer of 0 to 5,000;and b represents an integer of 3 to 20; and wherein said esterificationor transesterication catalyst is a tin compound.
 4. A process ofproducing a random siloxane copolymer comprising the step of reacting atleast one diol, at least one dicarbonate, and a silicone compound ascopolymerization components in the presence of an esterification or atransesterification catalyst, wherein said silicone compound is at leastone selected from the group consisting of compounds represented by thegeneral formulas (I) and (II):

wherein R¹, R², R³, and R⁴ are each independently a hydrogen atom, ahalogen atom, a hydroxyl group, or a substituted- or non-substitutedorganic group, X and Y are each independently selected from the groupconsisting of an alkoxy group, a phenoxy group, a non-substitutedorganic hydrocarbon or a substituted organic hydrocarbon wherein atleast one or more hydrogen atoms may be independently replaced with oneor more substituents selected from the group consisting of a hydroxylsubstituent, a halogen atom, an amino substituent, an ammoniumsalt-containing substituent, an alkylamino substituent, a carboxylsubstituent, an ester substituent, a polyether substituent, an epoxysubstituent, a vinyl substituent, a vinylether substituent, a vinylester substituent, an allyl substituent, an acryl substituent, amethacryl substituent, a mercapto substituent, and an isocyanatesubstituent; a represents an integer of 0 to 5000; and b represents aninteger of 3 to
 20. 5. The process according to claim 4, wherein X and Yare each independently selected from the group consisting of a methylgroup, a phenyl group, a methoxy group, an ethoxy group and a phenoxygroup.
 6. The process according to claim 5, wherein X and Y are eachindependently selected from the group consisting of a methyl group and amethoxy group.